The program proposed is the continuation of the grant initially awarded in 1975 to study infections in patients with malignant disease. The primary approach to this investigation is to study techniques for preventing infection in high risk patients, particularly those exposed to myelosuppressive activity either of the disease or the therapy. Appropriate recipients receiving intensive chemotherapy with sufficient numbers of available donors are utilized in this study to receive prophylactic granulocyte transfusions during the periods of severe myelosuppression. The incidence, duration and type of infections are being identified in this group of patients and compared with a similar group of patients in whom insufficient donors are available but who are receiving the same chemotherapeutic agents on the same program.